1. Field of the Invention
This invention relates in general to oil and gas recovery, in particular to the optimization of production and injection rates, and more specifically to systems, program product, and methods that provide improved well performance modeling, building, and calibration.
2. Description of the Related Art
An oil and gas reservoir is generally composed of porous and permeable rock which contains the oil and gas (and other hydrocarbons) in its pores. The oil and gas stored in the reservoir is prevented from reaching the surface due to an impermeable rock. The oil and gas within the reservoir can exert a substantial amount of vertical pressure on the impermeable rock. Portions of an oil and gas well can be run through the non-permeable rock to access the oil and gas in the reservoir. The typical oil and gas well can be thought of as a hole in the ground in which a steel pipe called a casing is placed. The annular space between the casing and the formation rock is filled with cement, ideally resulting in a smooth steel lined hole in the ground passing through the reservoir. In a process called completion, holes are generated in the casing at the reservoir depth to allow oil and gas to enter the well, and another smaller pipe hanging from the surface wellhead is added that allows the oil and gas to be brought to the surface in a controlled manner.
Well models are heavily used for production optimization, designing well completions, and creating well performance tables for reservoir simulation studies. Well production and injection modeling is a process practiced daily by many disciplines within the oil and gas industry. Petroleum engineers rely heavily on well modeling after analyzing and evaluating a wide range of data that influence well productivity to predict and optimize production and injection rates. Conventionally, many of the well modeling users do not follow a standard method in feeding the correct data into the simulator nor in the performance calibration step. The process is lengthy and subject to human input errors.
There can be significant benefits in modeling each well individually. Creating the individual well model, however, can be expected to require inputting and processing a considerably large amount of data usually scattered across entity databases. Once the well model is created, the predicted production and injection rates can be matched up against the field measured rates. The match can be attained by calibrating the models using, for example, a sensitivity analysis.
Conventionally, this well performance model creation and calibration process can be very lengthy and challenging, and is subject to human errors. The average time required to complete this task has been found to take up to 3-5 hours per well. The engineers' valuable time is mostly consumed by collecting/gathering the data, importing the data as necessary, and validating it, whereas such time should instead be used for design, analysis and decision making.
The data gathering and importing process involves dealing with several data components that need filtration, QC or validation before entering them into a well model, which is subject to human input error and inaccurate judgment. In addition, after building a well model, the calibration step is also subject to wrong, inaccurate or inefficient practices. Further, such process can result in a relatively long software license utilization time because the engineers normally leave the software running for many hours, especially when the process is interrupted for any reason.
Accordingly, recognized by the inventor is the need for systems, program product, and methods which can provide accurate, reliable and error-free well performance models that can be delivered in a timely manner. Also, recognized by the inventor is the need for systems, program product, and methods which can serve to eliminate the manual process of browsing and searching for multiple data components scattered in several database repositories and manually feeding them into well modeling software, which applies scientific techniques to build the well model and history match it, and which provides an interactive interface for customized calibration allowing users to override data used in model history matching and select the calibration parameters.
Further, recognized by the inventor is the need for systems, program product, and methods that addresses all of the above problems, that capture the “best practices” and experience of the engineers, and that provides a standardized scientific approach that essentially guarantees creating accurate and calibrated well models within a fraction of the time allotted according to conventional processes.